Does this sound like a bad fuel pump?

[Bruty74]

My 01 GP sputters and jerks when you get on the gas or go up a hill. It seems to run good when going down the road at a steady speed but when you need more power is when it acts up! It had a total tune up not long ago and also a new fuel filter. My mechanic wants to put a new fuel pump in but want to get a 2nd opinion before I shell out 300 big ones. Has anyone else had a problem like this?

[SyntheticShield]

There are just a ton of things that you could check before going to the fuel pump. It could be the fuel pressure regulator to start with. The sure fire way to check the operation of the fuel pump, well at least one of the best ways, is to check the fuel pressure at the schrader valve. And quite frankly I would be skeptical of any mechanic that wanted to replace a fuel pump without checking fuel pressure to begin with.

Are there any other symptoms? Hard shifting, late shifting, stalling, SES codes, etc?

I would fully expect that if the fuel pump were failing to the point of causing those kinds of symptoms that the SES light would trip and you would see a code from the O2 sensors along the lines of a lean condition.

I would check a few things first regarding the operation of the fuel pump before you give the okay to replace it, and again, if the mechanic has not done this I would be a little suspicious. Sorry if you two are good friends or family or something like that, but thats just how I would view that.

[stanwich]

since this topic is pretty close to a problem im having maybe you guys could give me a little input, when i start my car and idle it sounds like its missing, kinda has a shuddering idle, when i put it into gear and drive it seems fine, any ideas, is there a way to adjust my idle rpm.. im trying a new fuel filter this weekend but if anyone else has had this occur id love to hear about it

[FlatlinerD]

I have to agree with Syn.Shield on that issue. It does sound like the fuel pressure regulator. I had the same problem a couple of years ago. Turned out to be my fuel pump resistor because I have a GTP. Again, check for fuel pressure at the schrader valve after turning your ignition. To me, that's the dead giveaway. If you are getting pressure, then have your mechanic check the fuel pump resistor. If you are NOT getting pressure, then I would bet it's your fuel pump. Last but not least my best guess is that it is your fuel pump especially if this is your first ever problem with it and considering your "01" model 7 years on the road. Those puppies don't last forever. Oh, and get ready for more part-replacement-fun.

D. Craddock
1997 SE - beater/son's ride- Mods to come soon.
1999 GTP - 9in KnN CAI, 3.4 pulley, few other mods.
2000 Mitsu. Eclipse
1991 Assssstro Van - Fam. Mule

[Quicklynx]

My car is having the exact same problem. As Synthetic asked, my car is shifting hard, and stalling out at idle and initial acceleration. As stanwich describes on his car, my car also has misfire sounds when at idle, and shudders when I give it some gas. I did some research, and as FlatlinerD described, he needed a new fuel pump resistor. I have 131,xxx miles on my car, so I'm thinking this could also be an issue. I did a scan on my HPTuners and these are the codes I got.

P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency (History)(Immature)
P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage (SES)(Old)(History)(Current)(Immature)
P0141 HO2S Heater Performance Bank 1 Sensor 2 (Old)(Immature)
P1111 Intake Air temperature (IAT) Sensor Circuit Intermittent High Voltage (Old)(History)(Current)(Immature)

I guess the good news is I didn't get any of the codes mentioned on Dave's transmission information page on his website, Triple Edge Performance. 4T65E Transmission Info
However, while coming into work tonight, I stopped at a red light. Luckily it was right next to my job. It was around 11:40PM. My car surged and started accelerating. I eased off the brake to prepare for worst case scenario red line. It did this several times at the light. The P1811 code never went off. Dave said on his website, "this code will not set the SES light but will disable all adaptive shifts and will max out line pressure in the transmission which causes the harsh shifts and can also cause the transmission pump to whine because it is supplying fluid at a high rate and pressure and puts more stress on it thus creating the whine. Generally shutting off the car will make this condition go away until you drive a few more miles or the vehicle warms up and the harsh shifting will return." (tripleedgeperformance.com) The harsh shifting does disappear after I turn off the car, and it starts increasing slowly on my trip to home, and to work. I don't notice any transmission pump whining, but maybe I don't know exactly what I'm listening for.

This issue is what leads me to believe I have two separate problems rather than one. I think I need to replace my Pressure Control (EPC) Solenoid, which according to Dave's website, is the problem. Any more information would be well appreciated on replacing this part. Dave's website said I'll have to hoist the engine, drop the transmission, remove the driver side axle, and more. However that was a generalization of what will probably be done on a wide range of front wheel drive cars. I need the information for the 4T65E-HD.

By the way, my transmission fluid level is fine, as well as it's texture seems to be good, just to clear this issue out of the way. I had been checking my transmission fluid since the first sign of harsh shifting, and checked it tonight around 1:00AM after the surge attack.

I think for my other issues of stalling, and shuddered acceleration I will replace or upgrade the parts needed.

First of all, my IAT sensor seems to be damaged, and this may have been my fault. When I made my intake I didn't cut a bung for it, and let it hang. It may have been damaged while bobbling around. I don't think this is the cause of my problems, but probably could effect them to an extent. The sensor is now installed into TDC Racings intake. Luckily for me, I ordered a new sensor from Reptile earlier this week, so this issue should be fixed, no problem.

I am also going to change my fuel filter. I was going to change it anyways. Any suggestions on what brand filter I should go with, or should I just stick to GM?

The Fuel Pressure regulator check seems like a good idea. I will try that. I will probably just go ahead and replace it with an aftermarket piece because with what I plan on doing to my car, I'm going to need a high flowing one anyways.

Since these issues came up it may be a good idea to get a fuel pressure gauge. Where would be a good place to tap in a gauge on our cars to measure the pressure?

I may need to replace my fuel pump resistor as well. Fuel Pump Resistor - 97-03 Grand Prix - PFYC

I have a few Walbro 255lph HP fuel pumps lying around from my Talon. I think I'll put one on along with a fuel pump rewire kit. When I first installed a high flow pump on my Talon I noticed a loud wind sound coming from my car. I didn't realize it was the pump at the time, but after doing research on DSMtuners.com and other sites I discovered that the issue could be low voltage to the pump. I bought a rewire kit and sure enough the sound went away. I didn't have a pressure gauge on the car at the time so I don't know how much the flow increased, but their is a lot of feedback that says it is a needed upgrade.

Or my other option is this. http://www.3800performance.com/Merch...roduct_Count=3 It's a fuel pump rewire that bypasses the fuel pressure resistor. I think this is my best option because I wouldn't have to worry about the resistor anymore, and it would save me about $10-15 if buying the resistor and re-wire separately.

I think I'll throw in an alternator booster just for kicks as well.

Other potential problems could be I need to replace my Autolite 104's already.

Hopefully after all this my issues will be resolved. My fingers are crossed!!! Thanks to all who will help!

[GTX]

sounds like a MAF issue

[Scimmia]

For an 01 GP GT, don't forget about the catalytic converter. GM had a defect in the converters they used with the L36 in 01 and 02, and it can cause misfires when you need more power.

[Quicklynx]

sounds like a MAF issue

could be, the IAT sensor may be throwing it off, I now have a new one reptile sold me, so I'll see how it works

[chadb]

My 01 just had the same problem & i had to change the converter. $60.00. Easy fix.

[BADAZGTP]

I have a GTP, but I had a problem that when ever I had to give it more throttle than normal, merging into traffic or going up hill, it would sputter. Normal driving it was fine. Turned out I had a bad coil pack.

[cn1151]

I'm new here, but I would try testing the wiring first. Clear the codes after recording the information and see if any were from the( “It may have been damaged while bobbling around”) work you did. Good Luck

Rich

[boogsey]

I'm having the same problem as the first poster in this thread, my car (2000 NA GT) seems to shutter sometimes when accelerating. It doesn't happen all the time and it seems to happen much more often if I am above about 40mph. I never really notice it happening when accelerating from 0 to about 40mph. The fuel regulator makes some sense to me, but I am a little confused by why I wouldn't see the problem on a more regular basis. I'm also a little confused as to why I wouldn't be getting a check engine light if the fuel pressure regulator was the problem. I thought that you always got an error code if your car had misfired. I did get a flashing check engine light one time when I really hammered on it for a long time while it was shuttering (a little frustrated troubleshooting technique, obviously not the best idea). Before I could even pull over to stop the light went off and the car started running fine again. Any ideas, explanations, or other thought would be appreciated. Thanks!

[BADAZGTP]

When was the last time the fuel filter was changed?

[boogsey]

It's been a while. Probably close to 80,000 miles. I'll take that as a hint. Thanks.

[boogsey]

I replaced the fuel filter and am still having the problem. Any other ideas? Thanks

[cn1151]

I'm having the same problem as the first poster in this thread, my car (2000 NA GT) seems to shutter sometimes when accelerating. It doesn't happen all the time and it seems to happen much more often if I am above about 40mph. I never really notice it happening when accelerating from 0 to about 40mph. The fuel regulator makes some sense to me, but I am a little confused by why I wouldn't see the problem on a more regular basis. I'm also a little confused as to why I wouldn't be getting a check engine light if the fuel pressure regulator was the problem. I thought that you always got an error code if your car had misfired. I did get a flashing check engine light one time when I really hammered on it for a long time while it was shuttering (a little frustrated troubleshooting technique, obviously not the best idea). Before I could even pull over to stop the light went off and the car started running fine again. Any ideas, explanations, or other thought would be appreciated. Thanks!

The FPR would have little effect at 40MPH+ If the FPR was bad it would only increase fuel pressure. At 40+ vacuum is down and the FPR does not play as much of a roll. You need to get someone to test fuel pressure with and with out the vac line and scan for codes. If the CEL was flashing that is a good sign that something (Bad) is going on. With out this information it's going to be hard for anyone to help. Try the Zone or Advanced they can at least get you the codes. Do not let them clear anything until you think the problem is fixed.

Good luck
Rich

[TDCRacing]

My car is having the exact same problem. As Synthetic asked, my car is shifting hard, and stalling out at idle and initial acceleration. As stanwich describes on his car, my car also has misfire sounds when at idle, and shudders when I give it some gas. I did some research, and as FlatlinerD described, he needed a new fuel pump resistor. I have 131,xxx miles on my car, so I'm thinking this could also be an issue. I did a scan on my HPTuners and these are the codes I got.

P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency (History)(Immature)
P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage (SES)(Old)(History)(Current)(Immature)
P0141 HO2S Heater Performance Bank 1 Sensor 2 (Old)(Immature)
P1111 Intake Air temperature (IAT) Sensor Circuit Intermittent High Voltage (Old)(History)(Current)(Immature)

I guess the good news is I didn't get any of the codes mentioned on Dave's transmission information page on his website, Triple Edge Performance. 4T65E Transmission Info
However, while coming into work tonight, I stopped at a red light. Luckily it was right next to my job. It was around 11:40PM. My car surged and started accelerating. I eased off the brake to prepare for worst case scenario red line. It did this several times at the light. The P1811 code never went off. Dave said on his website, "this code will not set the SES light but will disable all adaptive shifts and will max out line pressure in the transmission which causes the harsh shifts and can also cause the transmission pump to whine because it is supplying fluid at a high rate and pressure and puts more stress on it thus creating the whine. Generally shutting off the car will make this condition go away until you drive a few more miles or the vehicle warms up and the harsh shifting will return." (tripleedgeperformance.com) The harsh shifting does disappear after I turn off the car, and it starts increasing slowly on my trip to home, and to work. I don't notice any transmission pump whining, but maybe I don't know exactly what I'm listening for.

This issue is what leads me to believe I have two separate problems rather than one. I think I need to replace my Pressure Control (EPC) Solenoid, which according to Dave's website, is the problem. Any more information would be well appreciated on replacing this part. Dave's website said I'll have to hoist the engine, drop the transmission, remove the driver side axle, and more. However that was a generalization of what will probably be done on a wide range of front wheel drive cars. I need the information for the 4T65E-HD.

By the way, my transmission fluid level is fine, as well as it's texture seems to be good, just to clear this issue out of the way. I had been checking my transmission fluid since the first sign of harsh shifting, and checked it tonight around 1:00AM after the surge attack.

I think for my other issues of stalling, and shuddered acceleration I will replace or upgrade the parts needed.

First of all, my IAT sensor seems to be damaged, and this may have been my fault. When I made my intake I didn't cut a bung for it, and let it hang. It may have been damaged while bobbling around. I don't think this is the cause of my problems, but probably could effect them to an extent. The sensor is now installed into TDC Racings intake. Luckily for me, I ordered a new sensor from Reptile earlier this week, so this issue should be fixed, no problem.

I am also going to change my fuel filter. I was going to change it anyways. Any suggestions on what brand filter I should go with, or should I just stick to GM?

The Fuel Pressure regulator check seems like a good idea. I will try that. I will probably just go ahead and replace it with an aftermarket piece because with what I plan on doing to my car, I'm going to need a high flowing one anyways.

Since these issues came up it may be a good idea to get a fuel pressure gauge. Where would be a good place to tap in a gauge on our cars to measure the pressure?

I may need to replace my fuel pump resistor as well. Fuel Pump Resistor - 97-03 Grand Prix - PFYC

I have a few Walbro 255lph HP fuel pumps lying around from my Talon. I think I'll put one on along with a fuel pump rewire kit. When I first installed a high flow pump on my Talon I noticed a loud wind sound coming from my car. I didn't realize it was the pump at the time, but after doing research on DSMtuners.com and other sites I discovered that the issue could be low voltage to the pump. I bought a rewire kit and sure enough the sound went away. I didn't have a pressure gauge on the car at the time so I don't know how much the flow increased, but their is a lot of feedback that says it is a needed upgrade.

Or my other option is this. Caspers Electronics Fuel Pump Hotwire Kit: 3800 Performance It's a fuel pump rewire that bypasses the fuel pressure resistor. I think this is my best option because I wouldn't have to worry about the resistor anymore, and it would save me about $10-15 if buying the resistor and re-wire separately.

I think I'll throw in an alternator booster just for kicks as well.

Other potential problems could be I need to replace my Autolite 104's already.

Hopefully after all this my issues will be resolved. My fingers are crossed!!! Thanks to all who will help!

you have a bad MAF sensor. That is why it is shifting hard. You also have a bad o2 sensor.

[TDCRacing]

My 01 GP sputters and jerks when you get on the gas or go up a hill. It seems to run good when going down the road at a steady speed but when you need more power is when it acts up! It had a total tune up not long ago and also a new fuel filter. My mechanic wants to put a new fuel pump in but want to get a 2nd opinion before I shell out 300 big ones. Has anyone else had a problem like this?

You have a bad coil pack.

[Farmboy87]

Quote:
Originally Posted by boogsey
I'm having the same problem as the first poster in this thread, my car (2000 NA GT) seems to shutter sometimes when accelerating. It doesn't happen all the time and it seems to happen much more often if I am above about 40mph. I never really notice it happening when accelerating from 0 to about 40mph. The fuel regulator makes some sense to me, but I am a little confused by why I wouldn't see the problem on a more regular basis. I'm also a little confused as to why I wouldn't be getting a check engine light if the fuel pressure regulator was the problem. I thought that you always got an error code if your car had misfired. I did get a flashing check engine light one time when I really hammered on it for a long time while it was shuttering (a little frustrated troubleshooting technique, obviously not the best idea). Before I could even pull over to stop the light went off and the car started running fine again. Any ideas, explanations, or other thought would be appreciated. Thanks!

I had a similiar problem on my old se turned out to be a plugged cat.

[TDCRacing]

Quote:
Originally Posted by boogsey
I'm having the same problem as the first poster in this thread, my car (2000 NA GT) seems to shutter sometimes when accelerating. It doesn't happen all the time and it seems to happen much more often if I am above about 40mph. I never really notice it happening when accelerating from 0 to about 40mph. The fuel regulator makes some sense to me, but I am a little confused by why I wouldn't see the problem on a more regular basis. I'm also a little confused as to why I wouldn't be getting a check engine light if the fuel pressure regulator was the problem. I thought that you always got an error code if your car had misfired. I did get a flashing check engine light one time when I really hammered on it for a long time while it was shuttering (a little frustrated troubleshooting technique, obviously not the best idea). Before I could even pull over to stop the light went off and the car started running fine again. Any ideas, explanations, or other thought would be appreciated. Thanks!

I had a similiar problem on my old se turned out to be a plugged cat.

Sounds like you have the TCC going out in you're trans.

Check this out.

engine issues - Pontiac Grand Prix Forums : Grandprix


Symptoms the same? Then that is it.